32 results on '"Xi‐Juan Liu"'
Search Results
2. Marsdenia tenacissima extract induces apoptosis and suppresses autophagy through ERK activation in lung cancer cells
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Yan-Na Jiao, Li-Na Wu, Dong Xue, Xi-Juan Liu, Zhi-Hua Tian, Shan-Tong Jiang, Shu-Yan Han, and Ping-Ping Li
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Marsdenia tenacissima extract (MTE) ,Apoptosis ,Autophagy ,ERK activation ,NSCLC ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 ,Cytology ,QH573-671 - Abstract
Abstract Background Marsdenia tenacissima is an herb medicine which has been utilized to treat malignant diseases for decades. The M. tenacissima extract (MTE) shows significant anti-proliferation activity against non-small cell lung cancer (NSCLC) cells, but the underlying mechanisms remain unclear. In this study, we explored the potential anti-proliferation mechanisms of MTE in NSCLC cells in relation to apoptosis as well as autophagy, which are two critical forms to control cancer cell survival and death. Methods The proliferation of H1975 and A549 cells was evaluated by MTT assay. Cell apoptosis was assessed by Annexin V and PI staining, Caspase 3 expression and activity. Autophagy flux proteins were detected by Western blot with or without autophagy inducer and inhibitor. Endogenous LC3-II puncta and LysoTracker staining were monitored by confocal microscopy. The formation of autophagic vacuoles was measured by acridine orange staining. ERK is a crucial molecule to interplay with cell autophagy and apoptosis. The role of ERK on cell apoptosis and autophagy influenced by MTE was determined in the presence of MEK/ERK inhibitor U0126. Results The significant growth inhibition and apoptosis induction were observed in MTE treated NSCLC cells. MTE induced cell apoptosis coexisted with elevated Caspase 3 activity. MTE also impaired autophagic flux by upregulated LC3-II and p62 expression. Autophagy inducer EBSS could not abolish the impaired autophagic flux by MTE, while it was augmented in the presence of autophagy inhibitor Baf A1. The autophagosome–lysosome fusion was blocked by MTE via affecting lysosome function as evidenced by decreased expression of LAMP1 and Cathepsin B. The molecule ERK became hyperactivated after MTE treatment, but the MEK/ERK inhibitor U0126 abrogated autophagy inhibition and apoptosis induction caused by MTE, suggested that ERK signaling pathways partially contributed to cell death caused by MTE. Conclusion Our results demonstrate that MTE caused apoptosis induction as well as autophagy inhibition in NSCLC cells. The activated ERK is partially associated with NSCLC apoptotic and autophagic cell death in response to MTE treatment. The present findings reveal new mechanisms for the anti-tumor activity of MTE against NSCLC.
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- 2018
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3. Human cytomegalovirus IE1 downregulates Hes1 in neural progenitor cells as a potential E3 ubiquitin ligase.
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Xi-Juan Liu, Bo Yang, Sheng-Nan Huang, Cong-Cong Wu, Xiao-Jun Li, Shuang Cheng, Xuan Jiang, Fei Hu, Ying-Zi Ming, Michael Nevels, William J Britt, Simon Rayner, Qiyi Tang, Wen-Bo Zeng, Fei Zhao, and Min-Hua Luo
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Immunologic diseases. Allergy ,RC581-607 ,Biology (General) ,QH301-705.5 - Abstract
Congenital human cytomegalovirus (HCMV) infection is the leading cause of neurological disabilities in children worldwide, but the mechanisms underlying these disorders are far from well-defined. HCMV infection has been shown to dysregulate the Notch signaling pathway in human neural progenitor cells (NPCs). As an important downstream effector of Notch signaling, the transcriptional regulator Hairy and Enhancer of Split 1 (Hes1) is essential for governing NPC fate and fetal brain development. In the present study, we report that HCMV infection downregulates Hes1 protein levels in infected NPCs. The HCMV 72-kDa immediate-early 1 protein (IE1) is involved in Hes1 degradation by assembling a ubiquitination complex and promoting Hes1 ubiquitination as a potential E3 ubiquitin ligase, followed by proteasomal degradation of Hes1. Sp100A, an important component of PML nuclear bodies, is identified to be another target of IE1-mediated ubiquitination. A C-terminal acidic region in IE1, spanning amino acids 451 to 475, is required for IE1/Hes1 physical interaction and IE1-mediated Hes1 ubiquitination, but is dispensable for IE1/Sp100A interaction and ubiquitination. Our study suggests a novel mechanism linking downregulation of Hes1 protein to neurodevelopmental disorders caused by HCMV infection. Our findings also complement the current knowledge of herpesviruses by identifying IE1 as the first potential HCMV-encoded E3 ubiquitin ligase.
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- 2017
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4. Human cytomegalovirus infection perturbs neural progenitor cell fate via the expression of viral microRNAs
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Xuan Jiang, Siqing Liu, Ya‐Ru Fu, Xi‐Juan Liu, Xiao‐Jun Li, Bo Yang, Hai‐Fei Jiang, Zhang‐Zhou Shen, Endalkachew Ashenafi Alemu, Pavel Vazquez, Yaping Tang, Mari Kaarbø, Michael A. McVoy, Simon Rayner, and Min‐Hua Luo
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Infectious Diseases ,Virology - Published
- 2023
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5. Genetic variation in glia–neuron signalling modulates ageing rate
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Kai Li, Haipeng Li, Zi-Qian Hao, Shi-Qing Cai, Xi-Juan Liu, Wen-Li Hu, Hong Li, Xin-Lei Kang, Jiang-An Yin, Yuan-Hong Shan, and Ge Gao
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Male ,0301 basic medicine ,Aging ,Pharyngeal pumping ,Longevity ,Population ,Polymorphism, Single Nucleotide ,Receptors, G-Protein-Coupled ,Sexual Behavior, Animal ,03 medical and health sciences ,Mitochondrial unfolded protein response ,Genetic variation ,medicine ,Animals ,Sirtuins ,Allele ,Caenorhabditis elegans ,Caenorhabditis elegans Proteins ,education ,Alleles ,Neurons ,Genetics ,education.field_of_study ,Multidisciplinary ,biology ,Dopaminergic Neurons ,Genetic Variation ,biology.organism_classification ,Genetics, Population ,030104 developmental biology ,medicine.anatomical_structure ,Ageing ,Unfolded Protein Response ,Pharynx ,Female ,Neuron ,Neuroglia ,Locomotion ,Serotonergic Neurons ,Signal Transduction - Abstract
The rate of behavioural decline in the ageing population is remarkably variable among individuals. Despite the considerable interest in studying natural variation in ageing rate to identify factors that control healthy ageing, no such factor has yet been found. Here we report a genetic basis for variation in ageing rates in Caenorhabditis elegans. We find that C. elegans isolates show diverse lifespan and age-related declines in virility, pharyngeal pumping, and locomotion. DNA polymorphisms in a novel peptide-coding gene, named regulatory-gene-for-behavioural-ageing-1 (rgba-1), and the neuropeptide receptor gene npr-28 influence the rate of age-related decline of worm mating behaviour; these two genes might have been subjected to recent selective sweeps. Glia-derived RGBA-1 activates NPR-28 signalling, which acts in serotonergic and dopaminergic neurons to accelerate behavioural deterioration. This signalling involves the SIR-2.1-dependent activation of the mitochondrial unfolded protein response, a pathway that modulates ageing. Thus, natural variation in neuropeptide-mediated glia–neuron signalling modulates the rate of ageing in C. elegans. Identifying the gene polymorphisms that are the foundations of variation in glia–neuron signalling in Caenorhabditis elegans provides insight into highly variable age-related declines in worm behaviours. The rate at which we age is highly variable. The roundworm Caenorhabditis elegans also shows variability in lifespan and age-related decline. Shi-Qing Cai and colleagues now show that polymorphisms in regulatory-gene-for-behavioural-ageing-1 (rgba-1) and the neuropeptide receptor gene npr-28 result in changes in the rate at which the worms age. rgba-1 encodes neuropeptides in glial cells that activate receptors encoded by npr-28 in neurons, leading to a reduction of SIR-2.1-mediated activation of UPRmt, which modulates ageing.
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- 2017
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6. Infected T98G glioblastoma cells support human cytomegalovirus reactivation from latency
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Elizabeth A. Fortunato, Fei Zhao, Hua Zhu, Xi-Juan Liu, Xiao Dong, Qiyi Tang, Jin-Yan Sun, Bo Yang, Xuan Jiang, Le Wen, Shuang Cheng, Ying-Zi Ming, Min-Hua Luo, Simon Rayner, and Wen-Bo Zeng
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0301 basic medicine ,Human cytomegalovirus ,IBMX ,viruses ,Green Fluorescent Proteins ,Cytomegalovirus ,Context (language use) ,Biology ,Article ,Green fluorescent protein ,03 medical and health sciences ,chemistry.chemical_compound ,Genes, Reporter ,1-Methyl-3-isobutylxanthine ,Cell Line, Tumor ,Virology ,medicine ,Humans ,Gene ,Staining and Labeling ,medicine.disease ,Virus Latency ,030104 developmental biology ,Bucladesine ,Lytic cycle ,chemistry ,Virus Activation ,Signal transduction ,Viral genome replication - Abstract
T98G cells have been shown to support long-term human cytomegalovirus (HCMV) genome maintenance without infectious virus release. However, it remains unclear whether these viral genomes could be reactivated. To address this question, a recombinant HCMV (rHCMV) containing a GFP gene was used to infect T98G cells, and the infected cells absent of infectious virus production were designated T98G-LrV. Upon dibutyryl cAMP plus IBMX (cAMP/IBMX) treatment, a serial of phenomena were observed, including GFP signal increase, viral genome replication, lytic genes expression and infectious viruses release, indicating the reactivation of HCMV in T98G-LrV cells from a latent status. Mechanistically, HCMV reactivation in the T98G-LrV cells induced by cAMP/IBMX was associated with the PKA-CREB signaling pathway. These results demonstrate that HCMV was latent in T98G-LrV cells and could be reactivated. The T98G-LrV cells represent an effective model for investigating the mechanisms of HCMV reactivation from latency in the context of neural cells.
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- 2017
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7. A typical 22q11.2 deletion syndrome and pseudohypoparathyroidism: A CARE compliant case report
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Jing-Yu Jia, Xi-Juan Liu, and Chen Yan
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Male ,Pediatrics ,medicine.medical_specialty ,Adolescent ,diagnosis ,Normal parathyroid hormone ,03 medical and health sciences ,Hyperphosphatemia ,0302 clinical medicine ,Seizures ,medicine ,DiGeorge Syndrome ,Humans ,Deletion syndrome ,030212 general & internal medicine ,Clinical Case Report ,Pseudohypoparathyroidism ,Proteinuria ,Hypocalcemia ,business.industry ,nephrotic syndrome ,pseudohypoparathyroidism ,General Medicine ,medicine.disease ,Recurrent croup ,Speech development ,030220 oncology & carcinogenesis ,22q11.2 deletion syndrome ,medicine.symptom ,business ,Nephrotic syndrome ,Multiplex Polymerase Chain Reaction ,Research Article - Abstract
Rationale: It is rare to find 22q11.2 deletion syndrome with pseudohypoparathyroidism in children. Furthermore, the phenotypic spectrum of this disorder varies widely. Patient concerns: A patient was diagnosed with pseudohypoparathyroidism at age 14 years because of convulsions, hypocalcemia, hyperphosphatemia, normal parathyroid hormone levels, and basal ganglia calcifications. Thereafter, the child presented with symptoms of nephrotic syndrome; subsequently, he was diagnosed with nephrotic syndrome at the local hospital. Diagnosis: At our hospital, multiplex ligation-dependent probe amplification confirmed that the patient had 22q11.2 deletion syndrome. Interventions: The patient continued to be treated with calcium supplements. Outcomes: Seizure activity and proteinuria ceased. Lessons: Signs of this syndrome include delayed speech development due to velofacial dysfunction, recurrent croup attacks during early childhood due to latent hypocalcemia, and mild dysmorphic features. The findings of this patient indicated that 22q11.2 deletion syndrome may include a wide spectrum of clinical findings and that this diagnosis needs to be considered for all patients presenting with hypocalcemia, regardless of age.
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- 2019
8. WDR5 Facilitates Human Cytomegalovirus Replication by Promoting Capsid Nuclear Egress
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Yanyi Wang, Yongxuan Yao, Michael A. McVoy, Jin-Yan Sun, Yun Miao, Qiyi Tang, Xi-Juan Liu, Wei Wang, Xian-Zhang Wang, Xuan Jiang, William J. Britt, Hong Yang, Simon Rayner, Bo Yang, Zhen-Li Huang, Fei Zhao, and Min-Hua Luo
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DNA Replication ,0301 basic medicine ,Human cytomegalovirus ,Cell Survival ,viruses ,Immunology ,Cytomegalovirus ,Genome, Viral ,Biology ,Virus Replication ,Microbiology ,Virus ,Cell Line ,03 medical and health sciences ,Capsid ,Interferon ,Virology ,medicine ,Humans ,RNA, Small Interfering ,Lung ,Host factor ,Gene knockdown ,Intracellular Signaling Peptides and Proteins ,Histone-Lysine N-Methyltransferase ,Viral Load ,Virus Internalization ,medicine.disease ,Virus-Cell Interactions ,Up-Regulation ,Protein Transport ,HEK293 Cells ,030104 developmental biology ,Viral replication ,Insect Science ,DNA, Viral ,RNA Interference ,Viral genome replication ,medicine.drug - Abstract
WD repeat-containing protein 5 (WDR5) is essential for assembling the VISA-associated complex to induce a type I interferon antiviral response to Sendai virus infection. However, the roles of WDR5 in DNA virus infections are not well described. Here, we report that human cytomegalovirus exploits WDR5 to facilitate capsid nuclear egress. Overexpression of WDR5 in fibroblasts slightly enhanced the infectious virus yield. However, WDR5 knockdown dramatically reduced infectious virus titers with only a small decrease in viral genome replication or gene expression. Further investigation of late steps of viral replication found that WDR5 knockdown significantly impaired formation of the viral nuclear egress complex and induced substantially fewer infoldings of the inner nuclear membrane. In addition, fewer capsids were associated with these infoldings, and there were fewer capsids in the cytoplasm. Restoration of WDR5 partially reversed these effects. These results suggest that WDR5 knockdown impairs the nuclear egress of capsids, which in turn decreases virus titers. These findings reveal an important role for a host factor whose function(s) is usurped by a viral pathogen to promote efficient replication. Thus, WDR5 represents an interesting regulatory mechanism and a potential antiviral target. IMPORTANCE Human cytomegalovirus (HCMV) has a large (∼235-kb) genome with over 170 open reading frames and exploits numerous cellular factors to facilitate its replication. HCMV infection increases protein levels of WD repeat-containing protein 5 (WDR5) during infection, overexpression of WDR5 enhances viral replication, and knockdown of WDR5 dramatically attenuates viral replication. Our results indicate that WDR5 promotes the nuclear egress of viral capsids, the depletion of WDR5 resulting in a significant decrease in production of infectious virions. This is the first report that WDR5 favors HCMV, a DNA virus, replication and highlights a novel target for antiviral therapy.
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- 2018
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9. Human Cytomegalovirus Immediate-Early 1 Protein Causes Loss of SOX2 from Neural Progenitor Cells by Trapping Unphosphorylated STAT3 in the Nucleus
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Min-Hua Luo, Han-Qing Ye, Christina Paulus, Huimin Xia, Wei Wang, Xi-Juan Liu, Michael Nevels, Bo Yang, Man Jiang, William J. Britt, Cong-Cong Wu, Thomas Harwardt, Xian-Zhang Wang, Xiao-Jun Li, and Xuan Jiang
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Human cytomegalovirus ,0303 health sciences ,biology ,viruses ,virus diseases ,biochemical phenomena, metabolism, and nutrition ,medicine.disease ,Neural stem cell ,3. Good health ,Cell biology ,03 medical and health sciences ,0302 clinical medicine ,SOX2 ,Transcription (biology) ,medicine ,biology.protein ,Phosphorylation ,STAT3 ,Transcription factor ,Neural cell ,030217 neurology & neurosurgery ,030304 developmental biology - Abstract
The mechanisms underlying neurodevelopmental damage caused by virus infections remain poorly defined. Congenital human cytomegalovirus (HCMV) infection is the leading cause of fetal brain development disorders. Previous work has linked HCMV to perturbations of neural cell fate, including premature differentiation of neural progenitor cells (NPCs). Here we show that HCMV infection of NPCs results in the loss of the SOX2 protein, a key pluripotency-associated transcription factor. SOX2 depletion maps to the HCMV major immediate-early (IE) transcription unit and is individually mediated by the IE1 and IE2 proteins. IE1 causes SOX2 down-regulation by promoting the nuclear accumulation and inhibiting the phosphorylation of STAT3, a transcriptional activator of SOX2 expression. Deranged signaling resulting in depletion of a critical stem cell protein is an unanticipated mechanism by which the viral major IE proteins may contribute to brain development disorders caused by congenital HCMV infection.IMPORTANCEHuman cytomegalovirus (HCMV) infections are a leading cause of brain damage, hearing loss and other neurological disabilities in children. We report that the HCMV proteins known as IE1 and IE2 target expression of human SOX2, a central pluripotency-associated transcription factor that governs neural progenitor cell (NPC) fate and is required for normal brain development. Both during HCMV infection and when expressed alone, IE1 causes the loss of SOX2 from NPCs. IE1 mediates SOX2 depletion by targeting STAT3, a critical upstream regulator of SOX2 expression. Our findings reveal an unanticipated mechanism by which a common virus may cause damage to the developing nervous system and suggest novel targets for medical intervention.
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- 2018
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10. Human Cytomegalovirus Immediate Early 1 Protein Causes Loss of SOX2 from Neural Progenitor Cells by Trapping Unphosphorylated STAT3 in the Nucleus
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Christina Paulus, Xian-Zhang Wang, Thomas Harwardt, Bo Yang, William J. Britt, Xi-Juan Liu, Han-Qing Ye, Huimin Xia, Cong-Cong Wu, Wei Wang, Min-Hua Luo, Xuan Jiang, Xiao-Jun Li, Man Jiang, Michael Nevels, Medical Research Council, Tenovus-Scotland, University of St Andrews. School of Biology, and University of St Andrews. Biomedical Sciences Research Complex
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0301 basic medicine ,Human cytomegalovirus ,STAT3 Transcription Factor ,QH301 Biology ,viruses ,Immunology ,NDAS ,Cytomegalovirus ,Brain damage ,Microbiology ,Immediate-Early Proteins ,03 medical and health sciences ,QH301 ,SOX2 ,Downregulation and upregulation ,Neural Stem Cells ,Virology ,medicine ,Humans ,Progenitor cell ,STAT3 ,Transcription factor ,Cells, Cultured ,biology ,SOXB1 Transcription Factors ,virus diseases ,biochemical phenomena, metabolism, and nutrition ,medicine.disease ,Neural stem cell ,Cell biology ,Virus-Cell Interactions ,030104 developmental biology ,Insect Science ,Host-Pathogen Interactions ,biology.protein ,medicine.symptom - Abstract
The mechanisms underlying neurodevelopmental damage caused by virus infections remain poorly defined. Congenital human cytomegalovirus (HCMV) infection is the leading cause of fetal brain development disorders. Previous work has linked HCMV infection to perturbations of neural cell fate, including premature differentiation of neural progenitor cells (NPCs). Here, we show that HCMV infection of NPCs results in loss of the SOX2 protein, a key pluripotency-associated transcription factor. SOX2 depletion maps to the HCMV major immediate early (IE) transcription unit and is individually mediated by the IE1 and IE2 proteins. IE1 causes SOX2 downregulation by promoting the nuclear accumulation and inhibiting the phosphorylation of STAT3, a transcriptional activator of SOX2 expression. Deranged signaling resulting in depletion of a critical stem cell protein is an unanticipated mechanism by which the viral major IE proteins may contribute to brain development disorders caused by congenital HCMV infection.IMPORTANCE Human cytomegalovirus (HCMV) infections are a leading cause of brain damage, hearing loss, and other neurological disabilities in children. We report that the HCMV proteins known as IE1 and IE2 target expression of human SOX2, a central pluripotency-associated transcription factor that governs neural progenitor cell (NPC) fate and is required for normal brain development. Both during HCMV infection and when expressed alone, IE1 causes the loss of SOX2 from NPCs. IE1 mediates SOX2 depletion by targeting STAT3, a critical upstream regulator of SOX2 expression. Our findings reveal an unanticipated mechanism by which a common virus may cause damage to the developing nervous system and suggest novel targets for medical intervention.
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- 2018
11. Semantic-based knowledge categorization and organization for product design enterprises
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Xi-juan Liu and Yinglin Wang
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Knowledge-based systems ,Multidisciplinary ,Knowledge management ,business.industry ,Knowledge integration ,Computer science ,Knowledge engineering ,Personal knowledge management ,Knowledge value chain ,Open Knowledge Base Connectivity ,Domain knowledge ,business ,Knowledge sharing - Abstract
Former knowledge engineering research aimed at boosting automatic reasoning. However recent knowledge management research focused on promoting the knowledge sharing and reusing among the people. Because of the different aims between the two directions, former knowledge representation schemata, such as rule based representation, frame from knowledge engineering research does not fit to the current knowledge management scenarios. In this paper, for the purpose of building knowledge management systems for product design enterprises, knowledge items are classified into seven types based on the semantics of their usage. Then their representations are discussed respectively. Based on the above classification, a knowledge representation meta-model and a basic domain ontology reference model for cooperative knowledge management systems are put forward. The reference model is an abstraction that can be reused and extended in knowledge management systems of different enterprises. Finally, the patterns of knowledge acquisition processes in cooperative knowledge management scenarios of product design processes are studied.
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- 2015
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12. MicroRNA miR-21 Attenuates Human Cytomegalovirus Replication in Neural Cells by Targeting Cdc25a
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Simon Rayner, Min-Hua Luo, Edward S. Mocarski, Michael A. McVoy, Guan-Hua Qiao, Bo Yang, Xi-Juan Liu, Zhang-Zhou Shen, Han-Qing Ye, Qiyi Tang, Cong-Cong Wu, Ling-Feng Miao, Jiafu Li, Xiao-Jun Li, Christian Davrinche, William J. Britt, Stéphane Chavanas, and Ya-Ru Fu
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Human cytomegalovirus ,CDC25A ,Cell cycle checkpoint ,viruses ,Immunology ,Population ,Cytomegalovirus ,Biology ,Virus Replication ,Microbiology ,Neural Stem Cells ,Downregulation and upregulation ,Virology ,microRNA ,medicine ,Humans ,cdc25 Phosphatases ,education ,Cells, Cultured ,education.field_of_study ,medicine.disease ,Virus-Cell Interactions ,Cell biology ,MicroRNAs ,Viral replication ,Insect Science ,Host-Pathogen Interactions ,Stem cell - Abstract
Congenital human cytomegalovirus (HCMV) infection is a leading cause of birth defects, primarily manifesting as neurological disorders. HCMV infection alters expression of cellular microRNAs (miRs) and induces cell cycle arrest, which in turn modifies the cellular environment to favor virus replication. Previous observations found that HCMV infection reduces miR-21 expression in neural progenitor/stem cells (NPCs). Here, we show that infection of NPCs and U-251MG cells represses miR-21 while increasing the levels of Cdc25a, a cell cycle regulator and known target of miR-21. These opposing responses to infection prompted an investigation of the relationship between miR-21, Cdc25a, and viral replication. Overexpression of miR-21 in NPCs and U-251MG cells inhibited viral gene expression, genome replication, and production of infectious progeny, while shRNA-knockdown of miR-21 in U-251MG cells increased viral gene expression. In contrast, overexpression of Cdc25a in U-251MG cells increased viral gene expression and production of infectious progeny and overcame the inhibitory effects of miR-21 overexpression. Three viral gene products—IE1, pp71, and UL26—were shown to inhibit miR-21 expression at the transcriptional level. These results suggest that Cdc25a promotes HCMV replication and elevation of Cdc25a levels after HCMV infection are due in part to HCMV-mediated repression of miR-21. Thus, miR-21 is an intrinsic antiviral factor that is modulated by HCMV infection. This suggests a role for miR-21 downregulation in the neuropathogenesis of HCMV infection of the developing CNS.IMPORTANCEHuman cytomegalovirus (HCMV) is a ubiquitous pathogen and has very high prevalence among population, especially in China, and congenital HCMV infection is a major cause for birth defects. Elucidating virus-host interactions that govern HCMV replication in neuronal cells is critical to understanding the neuropathogenesis of birth defects resulting from congenital infection. In this study, we confirm that HCMV infection downregulates miR-21 but upregulates Cdc25a. Further determined the negative effects of cellular miRNA miR-21 on HCMV replication in neural progenitor/stem cells and U-251MG glioblastoma/astrocytoma cells. More importantly, our results provide the first evidence that miR-21 negatively regulates HCMV replication by targeting Cdc25a, a vital cell cycle regulator. We further found that viral gene products of IE1, pp71, and UL26 play roles in inhibiting miR-21 expression, which in turn causes increases in Cdc25a and benefits HCMV replication. Thus, miR-21 appears to be an intrinsic antiviral factor that represents a potential target for therapeutic intervention.
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- 2015
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13. ORF7 of Varicella-Zoster Virus Is Required for Viral Cytoplasmic Envelopment in Differentiated Neuronal Cells
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Hai-Fei Jiang, Xuan Jiang, Xiao Dong, Simon Rayner, Wen-Bo Zeng, Lin Guo, Hong Yang, Min-Hua Luo, Xi-Juan Liu, Zhang-Zhou Shen, Yi-Ge Song, Fei-Long Yu, Tong Cheng, Hua Zhu, Jing Zhou, Fei Zhao, Jin-Yan Sun, and Wei Wang
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0301 basic medicine ,Cytoplasm ,Herpesvirus 3, Human ,viruses ,Cellular differentiation ,Immunology ,Genome, Viral ,Biology ,Virus Replication ,medicine.disease_cause ,Herpes Zoster ,Microbiology ,Virus ,Cell Line ,Neuroblastoma ,Viral Proteins ,03 medical and health sciences ,Capsid ,Viral Envelope Proteins ,Viral entry ,Virology ,medicine ,Humans ,Gene ,Neurons ,integumentary system ,Virion ,Varicella zoster virus ,virus diseases ,Cell Differentiation ,Virus Internalization ,biochemical phenomena, metabolism, and nutrition ,Virus-Cell Interactions ,030104 developmental biology ,Viral replication ,Cell culture ,Insect Science ,Viral genome replication ,Gene Deletion - Abstract
Although a varicella-zoster virus (VZV) vaccine has been used for many years, the neuropathy caused by VZV infection is still a major health concern. Open reading frame 7 (ORF7) of VZV has been recognized as a neurotropic gene in vivo , but its neurovirulent role remains unclear. In the present study, we investigated the effect of ORF7 deletion on VZV replication cycle at virus entry, genome replication, gene expression, capsid assembly and cytoplasmic envelopment, and transcellular transmission in differentiated neural progenitor cells (dNPCs) and neuroblastoma SH-SY5Y (dSY5Y) cells. Our results demonstrate that the ORF7 protein is a component of the tegument layer of VZV virions. Deleting ORF7 did not affect viral entry, viral genome replication, or the expression of typical viral genes but clearly impacted cytoplasmic envelopment of VZV capsids, resulting in a dramatic increase of envelope-defective particles and a decrease in intact virions. The defect was more severe in differentiated neuronal cells of dNPCs and dSY5Y. ORF7 deletion also impaired transmission of ORF7-deficient virus among the neuronal cells. These results indicate that ORF7 is required for cytoplasmic envelopment of VZV capsids, virus transmission among neuronal cells, and probably the neuropathy induced by VZV infection. IMPORTANCE The neurological damage caused by varicella-zoster virus (VZV) reactivation is commonly manifested as clinical problems. Thus, identifying viral neurovirulent genes and characterizing their functions are important for relieving VZV related neurological complications. ORF7 has been previously identified as a potential neurotropic gene, but its involvement in VZV replication is unclear. In this study, we found that ORF7 is required for VZV cytoplasmic envelopment in differentiated neuronal cells, and the envelopment deficiency caused by ORF7 deletion results in poor dissemination of VZV among neuronal cells. These findings imply that ORF7 plays a role in neuropathy, highlighting a potential strategy to develop a neurovirulence-attenuated vaccine against chickenpox and herpes zoster and providing a new target for intervention of neuropathy induced by VZV.
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- 2017
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14. Later Passages of Neural Progenitor Cells from Neonatal Brain Are More Permissive for Human Cytomegalovirus Infection
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Hui Yuan, Jiafu Li, Bo Yang, Kanghong Hu, Min-Hua Luo, Xiao-Jun Li, William J. Britt, Ling-Feng Miao, Jiang Xu, Han-Qing Ye, Ying-Liang Duan, Philip H. Schwartz, Cong-Cong Wu, Xing Pan, Xiao-Ling Chen, Guan-Hua Qiao, Xi-Juan Liu, Xiaohui Tian, Ya-Ru Fu, Jun Zheng, and Simon Rayner
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Human cytomegalovirus ,viruses ,Cellular differentiation ,Immunology ,Congenital cytomegalovirus infection ,Brain ,Cytomegalovirus ,Cell Differentiation ,Biology ,medicine.disease ,Cell morphology ,Microbiology ,Virology ,Neural stem cell ,Neural Stem Cells ,Viral entry ,Insect Science ,medicine ,Humans ,Serial Passage ,Stem cell ,Author Correction ,Cytopathic effect - Abstract
Congenital human cytomegalovirus (HCMV) infection is the most frequent infectious cause of birth defects, primarily neurological disorders. Neural progenitor/stem cells (NPCs) are the major cell type in the subventricular zone and are susceptible to HCMV infection. In culture, the differentiation status of NPCs may change with passage, which in turn may alter susceptibility to virus infection. Previously, only early-passage (i.e., prior to passage 9) NPCs were studied and shown to be permissive to HCMV infection. In this study, NPC cultures derived at different gestational ages were evaluated after short (passages 3 to 6) and extended (passages 11 to 20) in vitro passages for biological and virological parameters (i.e., cell morphology, expression of NPC markers and HCMV receptors, viral entry efficiency, viral gene expression, virus-induced cytopathic effect, and release of infectious progeny). These parameters were not significantly influenced by the gestational age of the source tissues. However, extended-passage cultures showed evidence of initiation of differentiation, increased viral entry, and more efficient production of infectious progeny. These results confirm that NPCs are fully permissive for HCMV infection and that extended-passage NPCs initiate differentiation and are more permissive for HCMV infection. Later-passage NPCs being differentiated and more permissive for HCMV infection suggest that HCMV infection in fetal brain may cause more neural cell loss and give rise to severe neurological disabilities with advancing brain development.
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- 2013
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15. Human cytomegalovirus infection dysregulates neural progenitor cell fate by disrupting Hes1 rhythm and down-regulating its expression
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Wen-Bo Zeng, Xi-Juan Liu, Min-Hua Luo, Xuan Jiang, Sheng-Nan Huang, Fei Zhao, and Jin-Yan Sun
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0301 basic medicine ,congenital, hereditary, and neonatal diseases and abnormalities ,endocrine system ,Cellular differentiation ,Immunology ,Notch signaling pathway ,Cytomegalovirus ,Down-Regulation ,Biology ,Cell fate determination ,03 medical and health sciences ,Neural Stem Cells ,Virology ,Neurosphere ,Humans ,HES1 ,Progenitor cell ,Cells, Cultured ,Cell Proliferation ,Cell Differentiation ,Neural stem cell ,Cell biology ,030104 developmental biology ,embryonic structures ,Host-Pathogen Interactions ,Molecular Medicine ,Transcription Factor HES-1 ,Stem cell ,Research Article - Abstract
Human cytomegalovirus (HCMV) infection is a leading cause of birth defects, primarily affecting the central nervous system and causing its maldevelopment. As the essential downstream effector of Notch signaling pathway, Hes1, and its dynamic expression, plays an essential role on maintaining neural progenitor /stem cells (NPCs) cell fate and fetal brain development. In the present study, we reported the first observation of Hes1 oscillatory expression in human NPCs, with an approximately 1.5 hour periodicity and a Hes1 protein half-life of about 17 (17.6 ± 0.2) minutes. HCMV infection disrupts the Hes1 rhythm and down-regulates its expression. Furthermore, we discovered that depleting Hes1 protein disturbed NPCs cell fate by suppressing NPCs proliferation and neurosphere formation, and driving NPCs abnormal differentiation. These results suggested a novel mechanism linking disruption of Hes1 rhythm and down-regulation of Hes1 expression to neurodevelopmental disorders caused by congenital HCMV infection.
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- 2017
16. Correction for Pan et al., Later Passages of Neural Progenitor Cells from Neonatal Brain Are More Permissive for Human Cytomegalovirus Infection
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Xing Pan, Ling-Feng Miao, Ying-Liang Duan, William J. Britt, Xi-Juan Liu, Xiao-Ling Chen, Simon Rayner, Bo Yang, Kanghong Hu, Hui Yuan, Xiaohui Tian, Ya-Ru Fu, Guan-Hua Qiao, Jun Zheng, Jiang Xu, Han-Qing Ye, Philip H. Schwartz, Jiafu Li, Cong-Cong Wu, Xiao-Jun Li, and Min-Hua Luo
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Human cytomegalovirus ,viruses ,Immunology ,Biology ,medicine.disease ,Microbiology ,Virology ,Neural stem cell ,Insect Science ,Neonatal brain ,medicine ,otorhinolaryngologic diseases ,Pathogenesis and Immunity ,Permissive - Abstract
Congenital human cytomegalovirus (HCMV) infection is the most frequent infectious cause of birth defects, primarily neurological disorders. Neural progenitor/stem cells (NPCs) are the major cell type in the subventricular zone and are susceptible to HCMV infection. In culture, the differentiation status of NPCs may change with passage, which in turn may alter susceptibility to virus infection. Previously, only early-passage (i.e., prior to passage 9) NPCs were studied and shown to be permissive to HCMV infection. In this study, NPC cultures derived at different gestational ages were evaluated after short (passages 3 to 6) and extended (passages 11 to 20) in vitro passages for biological and virological parameters (i.e., cell morphology, expression of NPC markers and HCMV receptors, viral entry efficiency, viral gene expression, virus-induced cytopathic effect, and release of infectious progeny). These parameters were not significantly influenced by the gestational age of the source tissues. However, extended-passage cultures showed evidence of initiation of differentiation, increased viral entry, and more efficient production of infectious progeny. These results confirm that NPCs are fully permissive for HCMV infection and that extended-passage NPCs initiate differentiation and are more permissive for HCMV infection. Later-passage NPCs being differentiated and more permissive for HCMV infection suggest that HCMV infection in fetal brain may cause more neural cell loss and give rise to severe neurological disabilities with advancing brain development.
- Published
- 2016
17. Tick-borne encephalitis virus induces chemokine RANTES expression via activation of IRF-3 pathway
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Xiaowei Zhang, Hanzhong Wang, Minhua Luo, Bingke Bai, Zhenhua Zheng, Xi-Juan Liu, Qinxue Hu, Zongqiang Cui, Bo Shu, Xiaohe Ma, and Panyong Mao
- Subjects
Male ,0301 basic medicine ,Chemokine ,medicine.medical_treatment ,Immunology ,Gene Expression ,Virus ,Encephalitis Viruses, Tick-Borne ,RANTES ,Mice ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,Neuroinflammation ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Chemokine CCL5 ,Mice, Inbred BALB C ,Gene knockdown ,IRF-3 ,biology ,Research ,General Neuroscience ,Brain ,Viral Load ,biology.organism_classification ,Tick-borne encephalitis virus ,030104 developmental biology ,Cytokine ,Neurology ,Cell culture ,biology.protein ,Female ,Interferon Regulatory Factor-3 ,Chemokines ,Signal transduction ,Encephalitis, Tick-Borne ,030217 neurology & neurosurgery ,Signal Transduction - Abstract
Background Tick-borne encephalitis virus (TBEV) is one of the most important flaviviruses that targets the central nervous system (CNS) and causes encephalitides in humans. Although neuroinflammatory mechanisms may contribute to brain tissue destruction, the induction pathways and potential roles of specific chemokines in TBEV-mediated neurological disease are poorly understood. Methods BALB/c mice were intracerebrally injected with TBEV, followed by evaluation of chemokine and cytokine profiles using protein array analysis. The virus-infected mice were treated with the CC chemokine antagonist Met-RANTES or anti-RANTES mAb to determine the role of RANTES in affecting TBEV-induced neurological disease. The underlying signaling mechanisms were delineated using RANTES promoter luciferase reporter assay, siRNA-mediated knockdown, and pharmacological inhibitors in human brain-derived cell culture models. Results In a mouse model, pathological features including marked inflammatory cell infiltrates were observed in brain sections, which correlated with a robust up-regulation of RANTES within the brain but not in peripheral tissues and sera. Antagonizing RANTES within CNS extended the survival of mice and reduced accumulation of infiltrating cells in the brain after TBEV infection. Through in vitro studies, we show that virus infection up-regulated RANTES production at both mRNA and protein levels in human brain-derived cell lines and primary progenitor-derived astrocytes. Furthermore, IRF-3 pathway appeared to be essential for TBEV-induced RANTES production. Site mutation of an IRF-3-binding motif abrogated the RANTES promoter activity in virus-infected brain cells. Moreover, IRF-3 was activated upon TBEV infection as evidenced by phosphorylation of TBK1 and IRF-3, while blockade of IRF-3 activation drastically reduced virus-induced RANTES expression. Conclusions Our findings together provide insights into the molecular mechanism underlying RANTES production induced by TBEV, highlighting its potential importance in the process of neuroinflammatory responses to TBEV infection. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0665-9) contains supplementary material, which is available to authorized users.
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- 2016
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18. Modeling of additive manufacturing process relevant feature in layer based manufacturing process planning
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Xi-juan Liu
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Engineering ,Engineering drawing ,Multidisciplinary ,Knowledge representation and reasoning ,business.industry ,Industrial engineering ,Knowledge-based systems ,Machining ,Computer-integrated manufacturing ,Relevant feature ,Schema (psychology) ,Computer-aided ,Case-based reasoning ,business - Abstract
Compared with general machining processes, additive manufacturing (AM) process has stabler planning route and limited process variables and this makes it to be more easily designed and planned with knowledge based systems and computer aided techniques. Case based reasoning approach is applied to the process planning of additive manufacturing in this paper. The concept of “AM process relevant design features” is proposed after the analysis of the characteristics of AM processes. The concept is used as the basis of the knowledge representation, and AM relevant feature graph is used as the case representation schema. The case retrieval method is discussed based on this graph. The case representation of a machine arm is given to illustrate the brief process of the proposed approach.
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- 2012
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19. Human Cytomegalovirus Infection Dysregulates the Localization and Stability of NICD1 and Jag1 in Neural Progenitor Cells
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Fei Zhao, Qiyi Tang, Xi-Juan Liu, Zhang-Zhou Shen, Stéphane Chavanas, Ling-Feng Miao, Bo Yang, Ya-Ru Fu, William J. Britt, Xiao-Jun Li, Hua Zhu, Michael A. McVoy, Min-Hua Luo, and Simon Rayner
- Subjects
Human cytomegalovirus ,JAG1 ,Cell type ,viruses ,Immunology ,Notch signaling pathway ,Biology ,Microbiology ,Viral Matrix Proteins ,Viral Proteins ,Neural Stem Cells ,Virology ,medicine ,Humans ,Serrate-Jagged Proteins ,Receptor, Notch1 ,Regulation of gene expression ,Protein Stability ,Calcium-Binding Proteins ,virus diseases ,Membrane Proteins ,medicine.disease ,Neural stem cell ,Cell biology ,Virus-Cell Interactions ,Gene Expression Regulation ,Insect Science ,Cytomegalovirus Infections ,Host-Pathogen Interactions ,Proteolysis ,Jagged-1 Protein ,Intercellular Signaling Peptides and Proteins ,Stem cell - Abstract
Human cytomegalovirus (HCMV) infection of the developing fetus frequently results in major neural developmental damage. In previous studies, HCMV was shown to downregulate neural progenitor/stem cell (NPC) markers and induce abnormal differentiation. As Notch signaling plays a vital role in the maintenance of stem cell status and is a switch that governs NPC differentiation, the effect of HCMV infection on the Notch signaling pathway in NPCs was investigated. HCMV downregulated mRNA levels of Notch1 and its ligand, Jag1, and reduced protein levels and altered the intracellular localization of Jag1 and the intracellular effector form of Notch1, NICD1. These effects required HCMV gene expression and appeared to be mediated through enhanced proteasomal degradation. Transient expression of the viral tegument proteins of pp71 and UL26 reduced NICD1 and Jag1 protein levels endogenously and exogenously. Given the critical role of Notch signaling in NPC growth and differentiation, these findings reveal important mechanisms by which HCMV disturbs neural cell developmentin vitro. Similar eventsin vivomay be associated with HCMV-mediated neuropathogenesis during congenital infection in the fetal brain.IMPORTANCECongenital human cytomegalovirus (HCMV) infection is the leading cause of birth defects that primarily manifest as neurological disabilities. Neural progenitor cells (NPCs), key players in fetal brain development, are the most susceptible cell type for HCMV infection in the fetal brain. Studies have shown that NPCs are fully permissive for HCMV infection, which causes neural cell loss and premature differentiation, thereby perturbing NPC fate. Elucidation of virus-host interactions that govern NPC proliferation and differentiation is critical to understanding neuropathogenesis. The Notch signaling pathway is critical for maintaining stem cell status and functions as a switch for differentiation of NPCs. Our investigation into the impact of HCMV infection on this pathway revealed that HCMV dysregulates Notch signaling by altering expression of the Notch ligand Jag1, Notch1, and its active effector in NPCs. These results suggest a mechanism for the neuropathogenesis induced by HCMV infection that includes altered NPC differentiation and proliferation.
- Published
- 2015
20. Human astrocytic cells support persistent coxsackievirus B3 infection
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Hanzhong Wang, Yan Liu, Bingke Bai, Panyong Mao, Qinxue Hu, Xi-Juan Liu, Zhenhua Zheng, Xiaowei Zhang, Bo Shu, and Zhenfeng Zhang
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Chemokine ,Coxsackie and Adenovirus Receptor-Like Membrane Protein ,viruses ,Immunology ,Blotting, Western ,Coxsackievirus Infections ,Fluorescent Antibody Technique ,Biology ,Coxsackievirus ,medicine.disease_cause ,Real-Time Polymerase Chain Reaction ,Virus Replication ,Microbiology ,Proinflammatory cytokine ,Viral Proteins ,Interferon ,Virology ,medicine ,Humans ,RNA, Messenger ,Cells, Cultured ,CD55 Antigens ,Interleukin-6 ,Reverse Transcriptase Polymerase Chain Reaction ,Stem Cells ,Interleukin-8 ,Virion ,virus diseases ,Interferon-beta ,biology.organism_classification ,Enterovirus B, Human ,Virus-Cell Interactions ,Viral replication ,Cell culture ,Insect Science ,Astrocytes ,biology.protein ,Enterovirus ,RNA, Viral ,Stem cell ,medicine.drug - Abstract
Enteroviruses can frequently target the human central nervous system to induce a variety of neurological diseases. Although enteroviruses are highly cytolytic, emerging evidence has shown that these viruses can establish persistent infections both in vivo and in vitro . Here, we investigated the susceptibility of three human brain cell lines, CCF-STTG1, T98G, and SK-N-SH, to infection with three enterovirus serotypes: coxsackievirus B3 (CVB3), enterovirus 71, and coxsackievirus A9. Persistent infection was observed in CVB3-infected CCF-STTG1 cells, as evidenced by prolonged detection of infectious virions, viral RNA, and viral antigens. Of note, infected CCF-STTG1 cells expressed the nonfunctional canonical viral receptors coxsackievirus-adenovirus receptor and decay-accelerating factor, while removal of cell surface chondroitin sulfate from CCF-STTG1 cells inhibited the replication of CVB3, suggesting that receptor usage was one of the major limiting factors in CVB3 persistence. In addition, CVB3 curtailed the induction of beta interferon in infected CCF-STTG1 cells, which likely contributed to the initiation of persistence. Furthermore, proinflammatory chemokines and cytokines, such as vascular cell adhesion molecule 1, interleukin-8 (IL-8), and IL-6, were upregulated in CVB3-infected CCF-STTG1 cells and human progenitor-derived astrocytes. Our data together demonstrate the potential of CCF-STTG1 cells to be a novel cell model for studying CVB3-central nervous system interactions, providing the basis toward a better understanding of CVB3-induced chronic neuropathogenesis.
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- 2013
21. WDR5 Facilitates Human Cytomegalovirus Replication by Promoting Capsid Nuclear Egress.
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Bo Yang, Xi-Juan Liu, Yongxuan Yao, Xuan Jiang, Xian-Zhang Wang, Hong Yang, Jin-Yan Sun, Yun Miao, Wei Wang, Zhen-Li Huang, Yanyi Wang, Qiyi Tang, Rayner, Simon, Britt, William J., McVoy, Michael A., Min-Hua Luo, and Fei Zhao
- Subjects
- *
CAPSIDS , *HUMAN cytomegalovirus , *INTERFERONS , *SENDAI virus , *FIBROBLASTS - Abstract
WD repeat-containing protein 5 (WDR5) is essential for assembling the VISA-associated complex to induce a type I interferon antiviral response to Sendai virus infection. However, the roles of WDR5 in DNA virus infections are not well described. Here, we report that human cytomegalovirus exploits WDR5 to facilitate capsid nuclear egress. Overexpression of WDR5 in fibroblasts slightly enhanced the infectious virus yield. However, WDR5 knockdown dramatically reduced infectious virus titers with only a small decrease in viral genome replication or gene expression. Further investigation of late steps of viral replication found that WDR5 knockdown significantly impaired formation of the viral nuclear egress complex and induced substantially fewer infoldings of the inner nuclear membrane. In addition, fewer capsids were associated with these infoldings and there were fewer capsids in the cytoplasm. Restoration of WDR5 partially reversed these effects. These results suggest that WDR5 knockdown impairs the nuclear egress of capsids, which in turn decreases virus titers. These findings reveal an important role for a host factor whose function(s) is usurped by a viral pathogen to promote efficient replication. Thus, WDR5 represents an interesting regulatory mechanism and a potential antiviral target. IMPORTANCE Human cytomegalovirus (HCMV) has a large (∼235-kb) genome with over 170 open reading frames and exploits numerous cellular factors to facilitate its replication. HCMV infection increases protein levels of WD repeat-containing protein 5 (WDR5) during infection, overexpression of WDR5 enhances viral replication and knockdown of WDR5 dramatically attenuates viral replication. Our results indicate that WDR5 promotes the nuclear egress of viral capsids, the depletion of WDR5 resulting in a significant decrease in production of infectious virions. This is the first report that WDR5 favors HCMV, a DNA virus, replication and highlights a novel target for antiviral therapy. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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22. [Influence of diazoxide on mitochondrial apoptosis in human renal tubular cells induced by serum obtained from neonates with asphyxia]
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Xi-juan, Liu, Wen-bin, Dong, Qing-ping, Li, Xiao-ping, Lei, Xue-song, Zhai, Tao, Xiong, Cun-liang, Deng, and Feng, Chen
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Membrane Potential, Mitochondrial ,Serum ,Asphyxia Neonatorum ,Caspase 3 ,Diazoxide ,Serine Endopeptidases ,Infant, Newborn ,Apoptosis ,Epithelial Cells ,High-Temperature Requirement A Serine Peptidase 2 ,Mitochondria ,Kidney Tubules, Proximal ,Mitochondrial Proteins ,Protein Transport ,Humans ,Cells, Cultured - Abstract
To study the influence of diazoxide on mitochondrial apoptosis pathway of human renal proximal tubular cells (HK-2 cells).Cultured HK-2 cells were inoculated on 6-well plates, according to stochastic tables law, and they were divided into normal serum-treated group (NSTG) , post-asphyxial serum treatment group (PSTG), and post-asphyxial serum and diazoxide treatment group (PSDTG). The serum from neonates 24 hours after asphyxia in a dilution of 20% (volume fraction) was used for challenge. Diazoxide in a final concentration of 100 mol/L, was used for intervention. The expression of caspase-3 was detected by immunohistochemical method. The translocation rate of Omi/HtrA2 and mitochondria membrane potential were determined by indirect immunofluorescence and confocal microscopy.Compared with that of NSTG, the expression of caspase-3 absorbance (A) value of HK-2 cells in PSTG was significantly increased (25.19 + or - 3.33 vs. 13.63 + or - 1.89, P0.01), the translocation rate of Omi/HtrA2 of HK-2 cells in PSTG was significantly increased [(56.01 + or - 5.30)% vs.(37.59 + or - 5.60)%, P0.01], mitochondrial membrane red/green fluorescence intensity ratio was decreased significantly (0.79 + or - 1.42 vs. 1.82 + or - 0.23, P0.01). Compared with the PSTG, the expression value of caspase-3 of HK-2 cells in PSDTG was significantly decreased (20.17 + or - 2.19), the translocation rate of Omi/HtrA2 of HK-2 cells in PSDTG was significantly decreased [(46.91 + or - 2.70)%], and mitochondrial membrane red/green fluorescence intensity ratio increased significantly (1.47 + or - 0.14), but did not recover to the same degree as that of the NSTG (all P0.01).The diazoxide may reduce the expression of caspase-3, intracellular translocation of Omi/HtrA2, and stability of mitochondrial membrane potential, thereby significantly alleviates HK-2 cells injury induced by post-asphyxial-serum of neonate.
- Published
- 2010
23. [Autologous regulatory T cells can suppress the proliferation of lymphoma cell line in vitro]
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Zhi-Tao, Ying, Jun, Guo, Jun, Ren, Yan, Kong, Zhi-Hong, Yuan, Xi-Juan, Liu, Chen, Zhang, Wen, Zheng, Yu-Qin, Song, Yun-Tao, Zhang, and Jun, Zhu
- Subjects
Male ,Mice, Inbred C57BL ,Transforming Growth Factor beta1 ,Mice ,Lymphoma ,Cell Line, Tumor ,Animals ,Forkhead Transcription Factors ,Cell Separation ,Flow Cytometry ,T-Lymphocytes, Regulatory ,Cell Proliferation ,Interleukin-10 - Abstract
This study was aimed to investigate the suppressive effect of regulatory T (Treg) cells on the T cell lymphoma EL4 cell line and to explore its mechanism. C57BL/6 Mouse Treg cells were isolated by MACS (magnetic cell sorting). The purity and the expression of Foxp3 were detected by flow cytometry. The suppressive effect of sorted Treg cells on EL4 cells was detected by MTT assay. The secretion of TGF-beta1 and IL-10 was examined by enzyme-linked immunosorbent assay (ELISA). The results showed that CD4(+)CD25(+) T cells could be successfully isolated by MACS with the purity reaching 91.6% and the expression level of Foxp3 was 78.9%. The ratio of viable cells was more than 95%. Regulatory T cells could suppress the proliferation of EL4 cells effectively in the presence of antigen presenting cells (APCs). And the suppressive effect was most significant at 1:1 ratio. In addition, the suppression still existed without APCs. TGF-beta1 and IL-10 could not be detected by ELISA. It is concluded that the Treg cells can suppress T lymphoma cell in vitro. The suppressive effect of Treg cells works in dose-dependent manner, but not in cytokine-dependent manner. The mechanism of this suppression may take effect through cell-cell contact.
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- 2009
24. [The signal transduction pathway and epigenetic pattern in learning and memory]
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Xi-Juan, Liu, Chen, Huang, and Zhang-Min, Yang
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Memory ,Long-Term Potentiation ,Animals ,Gene Expression ,Learning ,Hippocampus ,Epigenesis, Genetic ,Signal Transduction - Published
- 2008
25. Analysis of high-frequency stimulation-evoked synaptic plasticity in mouse hippocampal CA1 region
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Xi-Juan, Liu, Fen-Sheng, Huang, Chen, Huang, Zhang-Min, Yang, and Xin-Zheng, Feng
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Mice ,Neuronal Plasticity ,Long-Term Potentiation ,Animals ,Excitatory Postsynaptic Potentials ,Receptors, AMPA ,CA1 Region, Hippocampal - Abstract
Extracellular recordings of field excitatory postsynaptic potential (fEPSP) is one of the most common ways for studies of synaptic plasticity, such as long-term potentiation (LTP) and paired-pulse plasticity (PPP). The measurement of the changes in the different components of fEPSP waveform, such as the initial slope, initial area, peak amplitude and whole area, were commonly used as criteria for the judgement of potentiation or depression of synaptic plasticity. However, the differences in the conclusions drawn from measuring different components of fEPSP waveform at the same recording have still been largely ignored. Here we compared high-frequency stimulation (HFS)-evoked synaptic plasticity, both LTP and PPP, by measuring different components of fEPSP waveform, including the initial slope, initial area, peak amplitude, whole area and time course. The results not only indicated the acceleration of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor kinetics underlies LTP in hippocampal CA1 region of mice, but also showed that different measurements of fEPSP waveform at the same recording result in different magnitudes of LTP and different forms of PPP in hippocampal CA1 region of mice. After HFS, the paired-pulse ratio was slightly decreased by measurement of the initial area, but obviously increased by measurement of the initial slope of the pair fEPSPs. These results might draw apparently contradictory conclusions. Therefore, careful and complete analysis of the data from different parts of fEPSP waveforms is important for reflection of the faithful changes in synaptic plasticity.
- Published
- 2008
26. Towards a Semi-Automatic Ontology Mapping - An Approach Using Instance Based Learning and Logic Relation Mining
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Jie Wang, Ying-lin Wang, and Xi-juan Liu
- Subjects
Structure (mathematical logic) ,Relation (database) ,business.industry ,Computer science ,Knowledge engineering ,Machine learning ,computer.software_genre ,Graph (abstract data type) ,Domain knowledge ,Semantic integration ,Case-based reasoning ,Artificial intelligence ,Instance-based learning ,business ,computer - Abstract
To share information and knowledge of heterogeneous systems, one of the key issues is the mapping of their ontologies for interoperability. As manual mapping is too tedious, labor intensive, and prone to errors to support complex applications, investigating (semi-) automatic methods for ontology mapping becomes an imperative need. In recent years automatic ontology mapping arouses researchers? interests and valuable progresses have been made. However, there are still few reliable methods that have been successfully employed in real applications. In this paper we present a novel approach for systematically integrating all the available information including labels, instances, structures and former mapping experiences for semi-automatic mapping of heterogeneous ontologies. In this approach, we use four steps in making the decisions for mapping. Firstly we adopt an instance-based matching process that is a slight modification of GLUE to find the possible concept mappings between two ontologies. Secondly we use former indexed experiences that embed domain knowledge to modify the result. Thirdly a graph-based iteration process is executed in order to take the different information and knowledge structures into consideration. To eliminate negative efforts of structure heterogeneity we make a preprocessing for the structure reorganization via modifying the structures of ontologies before the iteration. Finally the attribute correspondences are identified through a mining and matching process for the logic relations among ontologies.
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- 2006
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27. Human Cytomegalovirus Infection Dysregulates the Localization and Stability of NICD1 and Jag1 in Neural Progenitor Cells.
- Author
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Xiao-Jun Li, Xi-Juan Liu, Bo Yang, Ya-Ru Fu, Fei Zhao, Zhang-Zhou Shen, Ling-Feng Miao, Rayner, Simon, Chavanas, Stéphane, Hua Zhu, Britt, William J., Qiyi Tang, McVoy, Michael A., and Min-Hua Luo
- Subjects
- *
HUMAN cytomegalovirus , *HUMAN cytomegalovirus diseases , *PROGENITOR cells , *NEURAL development , *DOWNREGULATION , *GENE expression - Abstract
Human cytomegalovirus (HCMV) infection of the developing fetus frequently results in major neural developmental damage. In previous studies, HCMV was shown to downregulate neural progenitor/stem cell (NPC) markers and induce abnormal differentiation. As Notch signaling plays a vital role in the maintenance of stem cell status and is a switch that governs NPC differentiation, the effect of HCMV infection on the Notch signaling pathway in NPCs was investigated. HCMV downregulated mRNA levels of Notch1 and its ligand, Jag1, and reduced protein levels and altered the intracellular localization of Jag1 and the intracellular effector form of Notch1, NICD1. These effects required HCMV gene expression and appeared to be mediated through enhanced proteasomal degradation. Transient expression of the viral tegument proteins of pp71 and UL26 reduced NICD1 and Jag1 protein levels endogenously and exogenously. Given the critical role of Notch signaling in NPC growth and differentiation, these findings reveal important mechanisms by which HCMV disturbs neural cell development in vitro. Similar events in vivo may be associated with HCMV-mediated neuropathogenesis during congenital infection in the fetal brain. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
28. Towards a Semi-Automatic Ontology Mapping - An Approach Using Instance Based Learning and Logic Relation Mining.
- Author
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Xi-Juan Liu, Ying-Lin Wang, and Jie Wang
- Published
- 2006
- Full Text
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29. MicroRNA miR-21 Attenuates Human Cytomegalovirus Replication in Neural Cells by Targeting Cdc25a.
- Author
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Ya-Ru Fu, Xi-Juan Liu, Xiao-Jun Li, Zhang-zhou Shen, Bo Yang, Cong-Cong Wu, Jia-Fu Li, Ling-Feng Miao, Han-Qing Ye, Guan-Hua Qiao, Rayner, Simon, Chavanas, Stéphane, Davrinche, Christian, Britt, William J., Qiyi Tang, Michael McVoy, Mocarski, Edward, and Min-Hua Luo
- Subjects
- *
CYTOMEGALOVIRUSES , *MICRORNA genetics , *CYTOMEGALOVIRUS diseases , *HUMAN abnormality genetics , *HUMAN abnormalities , *GENETICS , *GENE therapy , *DISEASE risk factors - Abstract
Congenital human cytomegalovirus (HCMV) infection is a leading cause of birth defects, primarily manifesting as neurological disorders. HCMV infection alters expression of cellular microRNAs (miRs) and induces cell cycle arrest, which in turn modifies the cellular environment to favor virus replication. Previous observations found that HCMV infection reduces miR-21 expression in neural progenitor/stem cells (NPCs). Here, we show that infection of NPCs and U-251MG cells represses miR-21 while increasing the levels of Cdc25a, a cell cycle regulator and known target of miR-21. These opposing responses to infection prompted an investigation of the relationship between miR-21, Cdc25a, and viral replication. Overexpression of miR-21 in NPCs and U-251MG cells inhibited viral gene expression, genome replication, and production of infectious progeny, while shRNA-knockdown of miR-21 in U-251MG cells increased viral gene expression. In contrast, overexpression of Cdc25a in U-251MG cells increased viral gene expression and production of infectious progeny and overcame the inhibitory effects of miR-21 overexpression. Three viral gene products--IE1, pp71, and UL26--were shown to inhibit miR-21 expression at the transcriptional level. These results suggest that Cdc25a promotes HCMV replication and elevation of Cdc25a levels after HCMV infection are due in part to HCMV-mediated repression of miR-21. Thus, miR-21 is an intrinsic antiviral factor that is modulated by HCMV infection. This suggests a role for miR-21 downregulation in the neuropathogenesis of HCMV infection of the developing CNS. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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30. Longevity Manipulations Differentially Affect Serotonin/Dopamine Level and Behavioral Deterioration in Aging Caenorhabditis elegans.
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Jiang-An Yin, Xi-Juan Liu, Jie Yuan, Jing Jiang, and Shi-Qing Cai
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AGING , *CAENORHABDITIS elegans , *NEUROTRANSMITTERS , *SEROTONIN , *DOPAMINE , *MITOCHONDRIAL physiology - Abstract
Aging is accompanied with behavioral and cognitive decline. Changes in the neurotransmitter level are associated with the age-related behavioral deterioration, but whether well-known longevity manipulations affect the function of neurotransmitter system in aging animals is largely unclear. Here we report that serotonin (5-HT) and dopamine (DA) level decrease with age in C. elegans. The reduction results in downregulation of the activity of neurons controlled by 5-HT/DA signaling, and deterioration of some important behaviors, including pharyngeal pumping, food-induced slowing responses, and male mating. Longevity manipulations differentially affect the age-related decline in neuronal level of 5-HT/DA. The reduction and resultant behavioral deterioration occur in long-lived worms with defective insulin signaling [daf-2(e1370), age-1(hx546)] or mitochondria function [isp-1(qm150), tpk-1(qm162)], but not in long-lived worms with dietary restriction eat-2(ad1116). A reduced expression level of dopa decarboxylase BAS-1, the shared enzyme for 5-HT/DA synthesis, is responsible for the decline in 5-HT/DA levels. RNAi assay revealed that the sustained 5-HT/DA level in neurons of aged eat-2(ad1116) worms requires PHA-4 and its effectors superoxide dismutases and catalases, suggesting the involvement of reactive oxygen species in the 5-HT/DA decline. Furthermore, we found that elevating 5-HT/DA ameliorates age-related deterioration of pharyngeal pumping, food-induced slowing responses, and male mating in both wild-type and daf-2(e1370) worms. Together, dietary restriction preserves healthy behaviors in aged worms at least partially by sustaining a high 5-HT/DA level, and elevating the 5-HT/DA level in wild-type and daf-2(e1370) worms improves their behaviors during aging. [ABSTRACT FROM AUTHOR]
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- 2014
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31. Later Passages of Neural Progenitor Cells from Neonatal Brain Are More Permissive for Human Cytomegalovirus Infection.
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Xing Pan, Xiao-Jun Li, Xi-Juan Liu, Hui Yuan, Jia-Fu Li, Ying-Liang Duan, Han-Qing Ye, Ya-Ru Fu, Guan-Hua Qiao, Cong-Cong Wu, Bo Yang, Xiao-Hui Tian, Kang-Hong Hu, Ling-Feng Miao, Xiao-Ling Chen, Jun Zheng, Rayner, Simon, Schwartz, Philip H., Britt, William J., and Jiang Xu
- Subjects
- *
PROGENITOR cells , *HUMAN cytomegalovirus diseases , *HUMAN abnormalities , *NEUROLOGICAL disorders , *CELL differentiation , *NEURAL development - Abstract
Congenital human cytomegalovirus (HCMV) infection is the most frequent infectious cause of birth defects, primarily neurological disorders. Neural progenitor/stem cells (NPCs) are the major cell type in the subventricular zone and are susceptible to HCMV infection. In culture, the differentiation status of NPCs may change with passage, which in turn may alter susceptibility to virus infection. Previously, only early-passage (i.e., prior to passage 9) NPCs were studied and shown to be permissive to HCMV infection. In this study, NPC cultures derived at different gestational ages were evaluated after short (passages 3 to 6) and extended (passages 11 to 20) in vitro passages for biological and virological parameters (i.e., cell morphology, expression of NPC markers and HCMV receptors, viral entry efficiency, viral gene expression, virus-induced cytopathic effect, and release of infectious progeny). These parameters were not significantly influenced by the gestational age of the source tissues. However, extended- passage cultures showed evidence of initiation of differentiation, increased viral entry, and more efficient production of infectious progeny. These results confirm that NPCs are fully permissive for HCMV infection and that extended-passage NPCs initiate differentiation and are more permissive for HCMV infection. Later-passage NPCs being differentiated and more permissive for HCMV infection suggest that HCMV infection in fetal brain may cause more neural cell loss and give rise to severe neurological disabilities with advancing brain development. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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32. Human Cytomegalovirus Immediate Early 1 Protein Causes Loss of SOX2 from Neural Progenitor Cells by Trapping Unphosphorylated STAT3 in the Nucleus.
- Author
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Cong-Cong Wu, Xuan Jiang, Xian-Zhang Wang, Xi-Juan Liu, Xiao-Jun Li, Bo Yang, Han-Qing Ye, Harwardt, Thomas, Man Jiang, Hui-Min Xia, Wei Wang, Britt, William J., Paulus, Christina, Nevels, Michael, and Min-Hua Luo
- Subjects
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CYTOMEGALOVIRUS diseases , *VIRUS diseases , *HUMAN cytomegalovirus , *PROGENITOR cells , *STEM cells - Abstract
The mechanisms underlying neurodevelopmental damage caused by virus infections remain poorly defined. Congenital human cytomegalovirus (HCMV) infection is the leading cause of fetal brain development disorders. Previous work has linked HCMV infection to perturbations of neural cell fate, including premature differentiation of neural progenitor cells (NPCs). Here, we show that HCMV infection of NPCs results in loss of the SOX2 protein, a key pluripotency-associated transcription factor. SOX2 depletion maps to the HCMV major immediate early (IE) transcription unit and is individually mediated by the IE1 and IE2 proteins. IE1 causes SOX2 downregulation by promoting the nuclear accumulation and inhibiting the phosphorylation of STAT3, a transcriptional activator of SOX2 expression. Deranged signaling resulting in depletion of a critical stem cell protein is an unanticipated mechanism by which the viral major IE proteins may contribute to brain development disorders caused by congenital HCMV infection. IMPORTANCE Human cytomegalovirus (HCMV) infections are a leading cause of brain damage, hearing loss, and other neurological disabilities in children. We report that the HCMV proteins known as IE1 and IE2 target expression of human SOX2, a central pluripotency-associated transcription factor that governs neural progenitor cell (NPC) fate and is required for normal brain development. Both during HCMV infection and when expressed alone, IE1 causes the loss of SOX2 from NPCs. IE1 mediates SOX2 depletion by targeting STAT3, a critical upstream regulator of SOX2 expression. Our findings reveal an unanticipated mechanism by which a common virus may cause damage to the developing nervous system and suggest novel targets for medical intervention. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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